I had a little time to look into some of your suggestions on my 85R model This weekend checked for cracked rims all appear to be in good shape. Checked all Lugnuts everything was good and tight Jacked her up and got all drive tires off the shop floor and got her in gear and rotated the drive tires and forward and reverse truck was quiet as can be . The sound is definitely coming from the trunnion . As you let the truck down off the jacks Trunnion seems to be bound up making metal on metal sound What you can hear in the earlier video You can watch the trunnion having a hard time get